How often do you get seen by the doctor when you have twins? (UK Only please)

Re

I paid for an early scan at 8 weeks and 5 days.

I had my booking in appt yesterday so I'm 9 weeks today.

I'm waiting on a letter for an appt with the scan but online it says that they try and scan you at 11 weeks but it's not clear how many times you are seen after that...

Help?!